Port catheters and port needles are known in the prior art. Port catheters are fixedly implanted subcutaneous plastic reservoirs connected to the central venous system in order to permit a reliable vascular access. A port catheter is applied when long-term or frequent vascular access is required. The port is usually composed of a chamber with a thick silicone membrane and an attached tube or catheter. After implantation of the port catheter, the access to the blood stream of the patient can be established by percutaneous insertion of what is called a port needle or Huber needle through the silicone membrane. The port needle lying in the chamber allows blood to be removed or allows a medicament to be administered by infusion. After application of the port needle, that is to say after the latter has been inserted into the silicone membrane of the port, and if the injection is intended to last a considerable time, the port needle is usually fixed in place with a sterile plaster in order to avoid shifting of the port needle or Huber needle. The port needle is usually changed after at most eight days, in order to avoid infections. After the port needle has been removed, the injection site is usually disinfected and covered with a sterile plaster. Port systems are known from DE 37 44 527 A1 or DE 37 19 238 A1, for example.